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- All Subjects: Water-supply
- Creators: Ariaratnam, Samuel T
Description
As urban populations grow, water managers are becoming increasingly concerned about water scarcity. Water managers once relied on developing new sources of water supply to manage scarcity but economically feasible sources of unclaimed water are now rare, leading to an increased interest in demand side management. Water managers in Las Vegas, Nevada have developed innovative demand side management strategies due to the cities rapid urbanization and limited water supply. Three questions are addressed. First, in the developed areas of the Las Vegas Valley Water District service areas, how did vegetation area change? To quantify changes in vegetation area, the Matched Filter Vegetation Index (MFVI) is developed from Mixture Tuned Match Filtering estimates of vegetation area calibrated against vegetation area estimates from high-resolution aerial photography. In the established city core, there was a small but significant decline in vegetation area. Second, how much of the observed decline in per capita consumption can be explained by Las Vegas land cover and physical infrastructure change that resulted from extensive new construction and new use of water conserving technology, and how much can be attributed to water conservation policy choices? A regression analysis is performed, followed by an analysis of three counter-factual scenarios to decompose reductions in household water into its constituent parts. The largest citywide drivers of change in water consumption were increased water efficiency associated with new construction and rapid population growth. In the established urban core, the most significant driver was declining vegetation area. Third, water savings generated by a conservation program that provides incentives for homeowners to convert grass into desert landscaping are estimated. In the city core, 82 gallons of water are saved in June for each square meter of landscape converted in the first year after conversion, but the savings attenuate to 33 gallons per meter converted as the landscape ages. Voluntary landscape conversion programs can generate substantial water savings. The most significant result is that the most effective way to ensure long term, sustainable reductions in water consumption in a growing city without changing water prices is to support the construction of water efficient infrastructure.
ContributorsBrelsford, Christina M (Author) / Abbott, Joshua K (Thesis advisor) / York, Abigail M (Thesis advisor) / Hanemann, W. Michael (Committee member) / McPherson, Timothy (Committee member) / Arizona State University (Publisher)
Created2014
Description
Nowadays there is a pronounced interest in the need for sustainable and reliable infrastructure systems to address the challenges of the future infrastructure development. This dissertation presents the research associated with understanding various sustainable and reliable design alternatives for water distribution systems. Although design of water distribution networks (WDN) is a thoroughly studied area, most researchers seem to focus on developing algorithms to solve the non-linear hard kind of optimization problems associated with WDN design. Cost has been the objective in most of the previous studies with few models considering reliability as a constraint, and even fewer models accounting for the environmental impact of WDN. The research presented in this dissertation combines all these important objectives into a multi-objective optimization framework. The model used in this research is an integration of a genetic algorithm optimization tool with a water network solver, EPANET. The objectives considered for the optimization are Life Cycle Costs (LCC) and Life Cycle Carbon Dioxide (CO2) Emissions (LCE) whereby the system reliability is made a constraint. Three popularly used resilience metrics were investigated in this research for their efficiency in aiding the design of WDNs that are able to handle external natural and man-made shocks. The best performing resilience metric is incorporated into the optimization model as an additional objective. Various scenarios were developed for the design analysis in order to understand the trade-offs between different critical parameters considered in this research. An approach is proposed and illustrated to identify the most sustainable and resilient design alternatives from the solution set obtained by the model employed in this research. The model is demonstrated by using various benchmark networks that were studied previously. The size of the networks ranges from a simple 8-pipe system to a relatively large 2467-pipe one. The results from this research indicate that LCE can be reduced at a reasonable cost when a better design is chosen. Similarly, resilience could also be improved at an additional cost. The model used in this research is more suitable for water distribution networks. However, the methodology could be adapted to other infrastructure systems as well.
ContributorsPiratla, Kalyan Ram (Author) / Ariaratnam, Samuel T (Thesis advisor) / Chasey, Allan (Committee member) / Lueke, Jason (Committee member) / Arizona State University (Publisher)
Created2012